This invention generally relates to surgical tools, methods, and systems for stabilizing, retracting, and/or inhibiting physiological movement of tissues. In a particular embodiment, the invention provides an endoscopic and optionally robotic surgical stabilizer for use during endoscopic and robotic surgical treatments on a beating heart.
Coronary artery disease remains a leading cause of morbidity and mortality, and particularly in industrialized societies. A number of approaches have been developed for treating coronary artery disease. While lifestyle changes, endovascular approaches (such as balloon angioplasty, atherectomy, and the like) and/or pharmaceutical treatments are often effective, in many cases it is necessary to resort to surgical procedures such as coronary artery bypass grafting to effectively treat coronary artery disease.
Coronary artery bypass graft (CABG) procedures are commonly performed using open-heart techniques. Conventional CABG procedures are described in U.S. Pat. No. 5,452,733 which is fully incorporated herein by reference. These open procedures generally involve dividing the patient's sternum and spreading the chest to provide access to the heart. The patient is placed on a cardiopulmonary bypass (CPB) machine, which oxygenates the patient's blood and pumps it through the patient's circulatory system during the surgical procedure. After the patient is on CPB, drugs (cardioplegia) are administered to temporarily stop the patient's heart to allow the grafting procedure to be performed. Conventional CABG procedures often involve bypassing a narrowed coronary artery by one of two methods. First, existing arteries can be dissected at one end from their natural attachments and transected to a location downstream of the narrowed portion of the coronary artery. The connection site of the graft and the artery is termed an anastomosis. Thus, arterial blood flowing through the existing artery bypasses the narrowing and outputs into the coronary artery which was previously restricted of flow. Second, artificial arterial shunts may be prepared by attaching a natural or synthetic blood vessel, typically a length obtained from a leg vein, at one end to the proximal ascending aorta and at the other end to the target location on a coronary artery downstream of the narrowing. The use of transected arteries is generally preferable since they tend to remain patent for long periods and require only one anastomosis.
When existing arteries are used to bypass a narrowing, the left or right internal mammary artery is often utilized. The left internal mammary artery is suitable as an arterial source for target locations on the left anterior descending coronary artery, the diagonal coronary artery, the circumflex artery/obtuse marginal artery, and the ramus intermedius coronary artery. The right internal mammary artery is available for connection to all of the same target locations, as well as the right coronary artery and the posterior descending artery. It will also be possible to use the gastroepiploic artery in the abdomen. When existing arteries are not available, veins or arteries may be harvested from other locations in a patient's body or synthetic grafts may be used. The grafts thus located will be attached at one end to the proximal ascending aorta (to provide the arterial blood supply) and at the other end to the target location on the coronary artery.
One drawback of conventional CABG procedures is the use of CPB. The use of CPB has been associated with an increased rate of stroke and neurological deficit. Consequently, techniques and devices have been proposed for performing open-heart surgery on a heart while the heart is beating. This eliminates the need for CPB. However, the grafting and anastomosis procedure is often more challenging on a beating heart than on a heart that has been stopped by cardioplegia. To reduce movement of the heart in the grafting area, a tool called a stabilizer is often used to engage the heart and stabilize the area of interest.
While elimination of CPB may improve the outcomes of many patients, the use of open-heart surgery to perform CABG is still highly traumatic to the patient. Thus, minimally invasive medical techniques for performing cardiac surgeries have recently been proposed. Here, the chest cavity is not opened; rather, the heart is accessed through ports or small incisions in the chest through which instruments are inserted. Arteries may be manipulated within the body to provide arterial blood supply to restricted coronary arteries. For example, access to the gastroepiploic artery can be obtained laparoscopically with the artery being brought into the thorax from the abdominal cavity via a window through the diaphragm. Likewise, grafts may be passed into the thorax through either an access trocar sheath or through the aorta (by punching a hole therethrough). These minimally invasive techniques are generally aimed at reducing the amount of extraneous tissue which is damaged during diagnostic or surgical procedures. This can effectively reduce the patient's recovery time, discomfort, and other deleterious side effects of cardiac surgery.
Unfortunately, both the proposed techniques for minimally invasive cardiac surgery and the proposed techniques for beating-heart cardiac surgery significantly increase the difficulty of these already complex surgical procedures. Formation of the anastomosis (the connection between the arterial source and the occluded artery) is quite challenging in a standard coronary artery bypass grafting procedure when the heart tissues are immobile and exposed for direct manipulation. Even skilled surgeons may find it awkward and/or time consuming to instead perform such procedure in a minimally invasive manner or while the heart is beating.
In robotically assisted surgery, the surgeon typically operates one or more master controllers to remotely control the motion of surgical instruments at the surgical site. The controller may be separated from the patient by a significant distance (for example, across the operating room, in a different room, or in a completely different building than the patient). Alternatively, the surgeon's work station with the controllers may be positioned quite near the patient in the operating room. Regardless, the controller will typically include one or more hand input devices, such as a joystick, exo-skeletal gloves, or the like. The hand input devices of the surgeon's workstation are generally coupled to the surgical instrument by a servomechanism. More specifically, servomotors move a manipulator, or “slave” supporting the surgical instrument based on the surgeon's manipulation of the hand input devices.
During a robotic surgical operation, a surgeon using a robotic surgical system may employ, via the manipulator, a variety of surgical instruments, such as tissue graspers, needle drivers, electrosurgical cautery probes, and the like. Each of these structures perform functions for the surgeon, for example, holding or driving a needle, grasping a blood vessel, dissecting, cauterizing, and/or coagulating tissue, and the like. The surgeon and/or an assistant will mount robotic surgical instruments having suitable end effectors to the manipulator, and will often pass the end effectors through cannula sleeves to an internal surgical site, so as to treat the targeted tissues while minimizing injury to the adjacent tissue structures.
In light of the above it would be desirable to provide medical devices, systems, and methods which would facilitate robotically performed endoscopic surgery on tissues undergoing physiological movement. It would be particularly desirable if these devices, systems and methods facilitated coronary artery bypass grafting on a beating heart under closed-chest conditions. It would further be beneficial to provide means for occluding the vessel or coronary artery during the procedure which are independent of the instrumentation so that the vessel may remain occluded while the instrumentation is repositioned. At least some of these objectives will be met by the present invention.